Work = (force) x (distance)
80 J = (force) x (4 m)
Force = (80 J) / (4 m) = 20 N
That's IF the force was in the same direction as the 4m of motion.
If the force was kind of slanted, then it had to be stronger, and
it had a component of 20N in the direction of the motion.
As the water russhes toward the shore, it rises because it is pushing against it.<span />
I like playing basketball. So I'm the object in motion. Until an unbalanced force comes and hits me I fall and stay at rest.
You would be correct.
Because you have only JUST released the arrow, and how close he is to the target, it would have the same amount of energy when it strikes the target. Yes, the kinetic energy would be destroyed when you hit the target but not right away. And yes, the potential energy would also be destroyed once you release the arrow, but it goes straight back once it stops moving, aka when it hits the target, although it has only just stopped moving.
Hope this helps!